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Biomedical subjects

M Lammens

Publications and source records attributed to M Lammens.

17 recordsLinked to original sources
PubMed1992

Further evidence for myelinated as well as unmyelinated fibre damage in a rat model of neuropathic pain.

A mononeuropathy, produced by ligation of the sciatic nerve in rats, has recently been proposed as an animal model of experimental pain and pain-related disorders (hyperalgesia and allodynia). We investigated quantitatively the morphological changes in myelinated and unmyelinated fibres of the sciatic nerves 2 weeks after ligation in rats exhibiting allodynia to thermal stimulation. There was a marked reduction in the number of large myelinated fibres distal to the ligature (711 +/- 34 compared with 5315 +/- 230 in normal nerves). We also found a significant loss of small myelinated fibres (2429 +/- 109 compared with 3197 +/- 308 in normal nerves), the remaining fibres of this type showing pathological properties. Finally, ultrastructural evidence of damage to unmyelinated fibres was found. The typical pattern of large clusters of normal unmyelinated axons was no longer present within most regions of the nerve. There was a significant reduction in the size of the unmyelinated fibres (0.41 micron +/- 0.15 compared with 0.71 micron +/- 0.08 in normal nerves), together with a twofold increase in their number per cluster. Hypotheses about the mechanism of thermal allodynia in this pain model therefore must take into account the fact that all fibre classes show pathological changes.

Animals↗
PubMed1992

Purulent meningitis due to aspergillosis in a patient with systemic lupus erythematosus.

We report a 39-year-old female patient with systemic lupus erythematosus under immunosuppressive therapy who developed persistent neutrophilic meningitis, for which no infectious agent could be identified. Intensifying the immunosuppressive therapy induced a short amelioration of the clinical picture. At autopsy, basal meningitis was found to be due to Aspergillus sp.

Adult↗
PubMed1992

Ethanol-induced disturbances of gliogenesis and neuronogenesis in the developing murine brain: an in vitro and in vivo immunohistochemical and ultrastructural study.

The effects of ethanol on murine brain development were studied in a model of whole embryo culture and in vivo. Ethanol locally enhances cell death in the primitive neuroepithelium. During neuronal migration, ethanol induces a premature transformation of the radial glial guides into astrocytes. Ethanol also inhibits the late gliogenesis. The resulting postmigratory neocortex displays an abnormal neuronal pattern almost completely deprived of vertical columnization. These glial-neuronal disturbances can explain neuropathological and clinical features of the fetal alcohol syndrome. Our study provides also an experimental tool for the study of cell death in normal and abnormal conditions at early stages of neurogenesis.

Animals↗
PubMed1992

MR imaging of intracranial aspergilloma extending from the sphenoid sinus in an immunocompromised patient with multiple myeloma.

A case of fatal intracranial aspergillosis, extending from the sphenoid sinus via the orbit into the subarachnoid space of the optochiasmatic cistern and the cistern of the middle cerebral artery is presented in an immunosuppressed patient with multiple myeloma. Adequate treatment was not instituted and the patient died because the condition was not recognised and interpreted as a soft tissue extension of an orbital localization of myeloma. MRI, especially after intravenous injection of Gadolinium, depicted very accurately the extension of the disease, as defined at autopsy.

Aspergillosis↗
PubMed1991

Extradural epidermoid tumor of the frontal bone.

The radiologic findings in a case of an extradural diploic epidermoid tumor (ET) of the frontal bone, examined with plain X rays, CT and MRI, are reported. A head injury with traumatic inclusion of epidermis could have been the origin of the tumor. This report stresses the importance of the plain skull X ray in the diagnosis of extradural ET.

Adult↗
PubMed1991

Paralysis of saccades and pursuit: clinicopathologic study.

We report a 73-year-old patient with an eye movement disorder characterized by paralysis of saccades and pursuit. At autopsy, there were small cortical lesions in the middle frontal gyrus immediately anterior to the precentral gyrus and in the inferior parietal lobule on both sides.

Aged↗
PubMed1991

Globoid cell leukodystrophy: a family with both late-infantile and adult type.

We present a patient with adult-onset globoid cell leukodystrophy (GBL) who had almost complete deficiency of galactosylceramide beta-galactosidase. A brother of the index patient deteriorated neurologically and died at the age of 4, probably from the late-infantile form of the disease. In this family, two clinical types of GBL are probably different expressions of an identical genotype.

Adult↗
PubMed1991

Acute hemorrhagic leukoencephalitis.

We report an autopsy proven case of acute hemorrhagic leukoencephalitis. There was a very rapid evolution leading to death in less than 24 hours. CT of the brain revealed widespread hypodensities in both frontal lobes. In the cerebrospinal fluid as well as in the peripheral blood, there was a moderate leucocytosis. The literature is reviewed.

Acute Disease↗
PubMed1976

In vitro action of bombesin and bombesin-like peptides on amylase secretion, calcium efflux, and adenylate cyclase activity in the rat pancreas: a comparison with other secretagogues.

Bombesin (a tetradecapeptide), the C-terminal nonapeptide of bombesin (bombesin-NP), and litorin (a parent nonapeptide), each stimulated amylase secretion from rat pancreatic fragments. These responses were not affected by atropine. The concentrations that produced half-maximal stumulation of secretion were 0.25 nM for bombesin, 0.30 nM for bombesin-NP, and 0.07 nM for litorin, as compared to 0.12 nM for caerulein and 0.80 muM for the cholinergic agent carbamylcholine. When used at maximal concentrations, bombesin, bombesin-NP, and litorin showed no action on cyclic AMP levels in the presence of 5 mM theophylline. By contrast, caerulein and secretin increased cyclic AMP levels by 27 and 208%, respectively. Bombesin, bombesin-NP, and litorin did not activate adenylate cyclase in a purified pancreatic plasma membrane preparation, whereas caerulein and secretin increased this activity 20 and 16-times, respectively...

Adenylyl Cyclases↗
PubMedDate not supplied

Prominent dural enhancement adjacent to nonmeningiomatous malignant lesions on contrast-enhanced MR images.

Prominent dural enhancement was noted in 10 (16%) of 61 superficial malignant intracranial tumors studied with contrast-enhanced MR imaging during a 2-year period. Included were six glioblastomas, three parenchymal metastases, and one case of dural metastasis. Seven patients had surgery. In four, there was extensive leptomeningeal invasion in the center of the lesion. In two of these lesions there was firm attachment of the center of the tumor to the dura, but without dural invasion despite extensive external carotid artery supply to the tumor in one case. In two cases the overlying dura was normal, and there was no leptomeningeal tumoral invasion. In the case of dural metastasis, huge nodular lesions were present along the inner aspect of the dura. In none of the cases did prominent dural enhancement adjacent to the tumor correspond with tumoral invasion or extension to the dura. Prominent dural enhancement on contrast-enhanced MR images appears to be much less frequent in malignant tumor than in meningioma, where it is seen in up to 60% of the cases. We believe this finding is more likely to represent reactive changes of the dura than tumoral invasion.

Brain Neoplasms↗
PubMedDate not supplied

Intracranial meningiomas: correlation between MR imaging and histology in fifty patients.

The magnetic resonance (MR) findings in 50 surgically verified intracranial meningiomas were reviewed. An attempt was made to correlate their signal intensity on spin echo (SE) T1-weighted, proton density [N(H)], and T2-weighted images with the different histologic subtypes. The T1-weighted images were nonspecific in differentiating the subtypes of meningiomas. On proton density and T2-weighted images, more information was available, but there remained large group (46%) of meningiomas that were not classifiable. The average signal intensity scores on T1-weighted, proton density, and T2-weighted images in the different histologic subtypes were correlated with each other using the Student t test. Only one significant correlation (psammomatous-anaplastic) and three almost significant correlations (syncytial-transitional or psammomatous and transitional-psammomatous) were found. Different histologic subtypes may have a different MR appearance, but this does not suffice to reach a histologic diagnosis by MR imaging.

Adult↗